Screen



Patented Feb. 8, 1927.

Uuirensra'rss atraen ALBERT H. STEBBINS, OIE" LOS ANGELES, CALIFORNIA.

SCREEN. Y

Appnation fired Maren s, 1926. serial No. 91,928.

' surface with suicient force to dislodgethe clogging particles are open to the objection that they subject the screening surface to severe stresses that tend to wear it out rapidly, and they may also seriously dis'- turb the proper siftingY or screening operation.

The present invention is thereforev directed to a screen the screening surface of which is. so constructed that the particles that i lodge in a slot may readily escape therefrom by traveling lengthwise of the slot until they escape from the end thereof.

One important feature of the present invention resides in a screening surface that is provided with a series of screening slots each of which increases in width in the direction in which the materials travel, and as a result of this construction the larger particles that lodge in a slot readily "work lengthwise of'thcsame in the direction in which its width increases to escape from the end of the slot.

Another feature of the invention resides in the construction whereby the sections of the screening surface are disposed in overlapping relation so that the materials that travel lengthwise of a slot may readily escape from the end thereof without escapino from the screening surface.

Other features, of the invention and novel combination of parts in addition to the above will be hereinafter described in connection with the accompanying drawings which illustrate one good practical form of the invention.

'1n the drawings Fig. 1 is a top plan view of a screenvconstructed in accordance with the present invention.

. Fig. 2 is a side elevation .of the screen .ing the sliding gate 13. In order to strengthen the casing and impart the desired of Fig. 1 shown mounted upona supporting frame, parts of the screen casing being broken away to show the material supporting surface. f Fig. 3 on an enlarged scale is a sectional perspective view of a portion of the screen of Fig. l.y Fig. 4 is an enlarged sectional view taken on the line 4 4 of Fig. 1; and ,f

Fig. 5 iD a top plan view of one of the ribs to be described. f The casing Vwhich is provided with the material supporting vsurface may be given any suitable shape or size, and the same may be mounted upon a frame for back and forth movement. as shown in Fig. 2 of the drawing, or if desired it may be supported at a relatively steep linclination inthe direc- Y tion of its length so that the materials being treated will iiow over the 'screening outl requiring the surface to be vibrated.

The screening casing shown in the draw- Y* of the material treatingicasing are provided Y the side walls 11 to which the floor 10.1nay be secured, and the materialitreating casing in the present case is shown as rectangular in shapeand as having the feedhopper 12 at the left-hand end thereof. The rate at which the materials flow from the feed hopper 12 may be regulated as desired by adjuststiffness to the same the iioor and side plates 11 may be secured to the channel irons i side'channels '14, as best shown: in Figs. lue

3 and 4. v v

If the screen` is to be vibrated to promote travel of the materialsV lengthwise of the same the screening surface may be sup` ported by any suitable meansV for back and 105 forth movement in the direction of its length. In the construction shown in Fig. 2 the screening casing is supportedat an inclinationV in thedirection of its length by a frame formed of the uprights 16 to'which 110 y surface under the influence of gravity withlil .cured tothe channel irons le' of the material treating. casing.V Y

The supporting `casing may be moved back and forth with a simple reciprocatory ymovement, or with a. progressive vibratory movement, vas may be desired, and the Ymeans fshown for imparting a vibratory movement to the` screening casing consists of la cable 2l an intermediate portion of which is rigidly secured to the casingby clamping means or the like. 22. The portion of the cable 2l extending from the clamping means 22 in the right-hand direction extends about a grooved sheave 23 which sheave is rotatably supported by a shaft 24 that is supported by bearing brackets 25- secured tothe supporting frame.

The portion of the cable2l that extends downwardly from the grooved sheave 23 is conveniently secured to a pipe-or hollow tube 26 the lower end lof which is threaded, andl the pipe or tuber 26 is yieldingly secured to the supporting frame. n spring 27T-is confined Abetween a transversely extendingbeam 28 secured to the supporting frame, and adjustable nuts 29y secured to theV threaded lower end of the tube 26. The arrangement is such that the spring 27 will exert a continuous pull upon the cable-2l that tends to move the screenV casing in a right-hand direction, and theV tension of the spring 27 may be adjusted as desired by adliustiirg the nuts 29 upon the tube 26. rlhe Ymeans shown for alternately pulling the screen casing in a left-hand direction and 'thenf releasing it' consists of a grooved sheave 30 about which is looped that por-I tion ofthe cable 21'wl1ich extends in a Y left-hand direction from the seciu'ing means 22, and the end portion of this cable extends from the lower face of the-sheave E30-"to anchoring lmeans 3l which may bev adjust-v Y ably secured to a transversely extending. l'ieam 32 of the frame. inountedupon an eccentric 3-3`which is rigidly secured to the driving sliaftB-i, and this The sheave 30 is shaft may be journaled in the bearing brackets Vthat are secured'to the supporting frame.

A yThe operating shaft 84 may be drirenby a. pulley or other means (not shown) andas this shaft rotates Vit turns `the eccentric 33 Y within the sheave. 30Y to move the latter Yback and forth towards and from the cable l tighteningposition to thereby pull the screen To this end a coiled'l rection in which the materials flow.

casing in a left-hand direction andthen reno essential part of the present invention,

but is shown and described to malreclear the construction and operation of the material supporting surface which will new be described. This material supporting surface in the construction shown is formed of a number of ribs 36 and these ribs are preferably mounted side by side to form vthe sections 37,. and the entire screen supporting surface is made of any desired number of the sections 37 disposed. lengthwise of the the casing in overlapping relation to each other; that is,the discharge end SSiof one section is disposed above and overlaps the leading end 39 of the next section. The sections 37 are preferably so disposed thatthe ribs of the successive sections lie in alignment with each other lengthwise 'of the casing so that a valley extending lengthwise of the casing is formedl between adjacent pairs of ribs. The ribs 36 may be formedfofsheet metal, cast iron or other material as desired, and these ribs are preferably somewhat V- shaped ink cross section as shown, ,the construction being such that eachrib is providedv with oppositely sloping sides which will direct the materials resting upon the ribs linto the valley formed between a pair of ribs.

`The screening of the materials being treated is effected by providing the screening surface with the slots l0 the size of which may be as large or as small as desired to accommodate the particular screening operation to be effected. rlhe fine particles which pass through the slots 40 fall upon the floor l0 of the casing and slide alongy the same towards the ri ght-hand end of the casing until they enter the discharge hopper' l-l. provided' for these materials. The coarse materials'which are unable to pass through the slots 40 will travel lengthwise of the screening surface over the successive sections 37 until they finally reach the discharge hopper 42 for thev coarse materials.

Each slot e0 is preferably constructed so that its width gradually increases in the di- This is desirable because the increasing width of the slots reduces the tendency of the larger particles to become stuck or lwedged in the slots. Since the sections 37 are disposed in overlappng relation to each other, and the slots 40 increase in Vthe direction of their lefigth, Jthe materials tl lodge in a' slot et() will readily lmove lengthwise of the same until theyv are able to pass through the wider portion of the slot 40, or until theyr` escape from the open end of the slot to fall upon the next section f3?.

In the construction shown the slots ed are formed by providing each rib 36' with y section.

the tapered side portions 43, as best shown in Fig. 5, and these tapered side portions preferably terminate a short distance from the wider end of the rib to form the portion 44 adapted to abut against asimilar portion of the adjacent rbl to thereby properly position the various ribs of a sectionv 37, as will be apparent from the'drawings.

In the'k construction shown the ribs 36 are secured to and are supported bythe transversely extending beams '45- that rest upon the channel irons 14 and l5, and as' stated each rib 36 is supported so thatit slopes upwardly in the direction ofy its length. To this end the wide portion 44 at the leading end of a' rib may rest upon a supporting beam 45, while the discharge end of the same rib is supported in spaced relation to the next transversely extending beam 45. A block 46 may be positioned between the leading end of each rib and'its supporting beam, while at the opposite or discharge end of each rib is provided a second block 47 which serves to space this end of the rib a substantial distance from the rib it overlaps, as will be apparent from the drawing. The various ribs may be clamped in their overlapping relation by bolts 48 extending through holes 49 formed in the ribs and through the supporting blocks 46 and 47 and beam 45, and each bolt 48 is secured in place by a nut 50. Each block 47 it should be noted has its lower end shaped to lit the V-shaped rib upon which it rests and the upper endv of each block 47 is shaped to lit the inner face of the rib it supports. As a result of this construction the overlapping ribs are held in alignment one above the other and are properly spaced laterally from each other.

The blocks 47 should supportrthe discharge end of a section 37 a sufficient distance above the leading end of the next section to prevent any particles such as (see Fig. 4) that extend downwardly a substantial distance through a slot from striking against the leading end 39 of the next This is important because if the particles which extend downwardly within the slots 40 are permitted to engage the leading end 39 of a rib or section, their movement in t-he slot will be arrested, thus causing clogging of the screen..

From the foregoing description, when read in* connection with the drawings, it will be seen that the screening surface forming the subject matter of the present invention is so constructed that the particles which lodge within the slots 40 may readily travel lengthwise of the slots until they escape fromthe ends thereof, whereupon they fall upon the next section ofthe screen to travel along the saine for further treatment. In this manner the particles which are too large to pass through a slot 40 are interfere with ject mattei' of the present invention not only prevents clogging, but also facilitates the usevv of a screen of maximum length, since the large particlesthat entera slot will notre main in theslot throughout'the entire length of the screen, but will escape therefrom upon f' reaching the end of a section. Furthermore,

the present construction may `readily be given suflicient strength to 4stand up under coarse, heavy fwork, and if a'riby becomes worn-or broken it Vmay readily be removedV and replaced by anew rib.

What is claimed is l. A screen for separating materials, comprising in combination, ka casing having a materialv supporting surface formed of a rr: multiplicity of separate ribs each havingv the shape of an inverted trough, means for supporting the ribs in rows extending lengthwise of the casing with their ends in overlapping relation, including spacer blocks having their lower' ends shaped to conform to the curved face of the ribs upon which they rest and their upper ends shaped to conform to the curved inner face of the ribs they support to thereby align the overlapping ribs, and flanges formed at the block' supporting. end of each rib for spacing the ribs laterally from each other to form slots between them.

2. A screen for separating materials, comprising in combination, a casing having a material supporting surface formed of a multiplicity of separate ribs each having a tti] longitudinally extending ridge, means for Vsupporting the ribs in rows extending lengthwise of the casing with their ends in overlapping relation, including spacer blocks mounted Vbetween the overlapping ends of the ribs and each rib having its lower face constructed to Vfit a ridge and thereby align one rib over the otheigand flanges formed at the block supporting end of each rib for spacing the ribs laterally from each other to form slots between them. c

3. A screen for separating materials, comprising in combination, a casing having a screening surface formed of a multiplicity of separate Aribs having downwardly slopingl sides, means for supporting the ribs in rows extending lengthwise of the casing with Vtheir endsin overlappingrelation, including spacer blocks between the overlapping ends of the ribs and each block having its lower end shaped to fit the downwardly sloping sides of the rib upon which it rests to thereby centre one rib over the other, and flanges between the ribs at the block supporting end of each'rib for spacin the ribs laterally from each other to form slots between them.

4. A screen for separating materials, com- 1 ses prising in combination, a casing having a screening surface formed of a multiplicity of ribs having downwardly sloping sides and spaced laterally Yto form slots between thein,

Y of the ribs and each block havingits lower Yend shaped tottfhe sloping sides of the rib upon which it rests to thereby centrerone rib over the other. v f

` 5. A screen for separating materials, comprising 1n combination, a casing having'a l5 screening surface Vformed of a multiplicity of ribs provided with faces that slope laterf ally from a central ridgeymeans adjacent the materialV receiving end of each rib Vfor spacing the ribs laterally apart to form slots between them, means .for supporting the ribs in rows extending lengthwise of the casing with their ends in overlapping relation7 and including spacer blocks between, the overlapping ends of the ribs and having their lower faces constructed to fit the Vlaterally sloping faces of the ribs to thereby insure centering of one rib over the othen c In testimony whereof, I have signed my vname to this specification.

ALBERT H. sTEBBINs@ 

